The present invention relates to a method of making a cosmetic cover comprising coating the interior of a mould with successive layers of one or more curable materials.
Such a method has already been proposed in which each layer contains different pigments at different loadings to produce the desired overall colouring for the cover.
One disadvantage of a cover made by such a method is that the colouring is not very realistic.
It is an aim of the present invention to obviate this disadvantage.
Accordingly, the present invention is directed to a method as set out in the opening paragraph of the present specification, in which at least an outer such layer is provided with means to create a non-homogeneous colour effect in that layer, and at least an inner such layer is provided with means to create a background colour, for the said outer layer, in the said inner layer.
It will be appreciated here that the outermost layer of the cover is the layer which is first-formed in the moulding.
The total number of layers with which the interior of the mould is coated may be three or more.
The said one or more curable materials may comprise a liquid monomer. Alternatively, or in addition, the said one or more materials may comprise a semi-liquid monomer.
The said means to create a non-homogeneous colour effect may be in the form of coloured lengths of fibres. Alternatively, they may comprise a variation in the thixotropy of the said one or more curable materials. Alternatively, the means to create a non-homogeneous colour effect may comprise dye-containing capsules having a form which will allow the passage of dye material within them into the layer during or after the curing process. Thus, the passing of the dye into the layer from the capsules may be caused by the curing process itself, or alternatively for example upon the exposure of the layer to sunlight.
Alternatively, such dyes could be introduced as solids, such as powders or crystals, or liquids directly into the layer.
The dyes used might be sensitive to light, such as for example polychromatic dyes.
The present invention extends to a method of making a coloured layer of material comprising introducing a dyestuff in a curable or cured layer to provide a non-homogeneous coloured layer.
The present invention also extends to a method of making a coloured layer of material comprising varying the thixotropy of one or more curable materials from which such a layer is made, thereby to produce a non-homogeneous colour effect in the layer.
An example of a method of making a cosmetic cover in accordance with the present invention is illustrated in the accompanying diagrammatic drawings, in which: